How IQ and Mental Age are Related?

Intelligence is measured by means of mental tests which are samples of ; various kinds of behaviour. Intelligence of a child is inferred from what he does and what he knows.

The units in which intelligence is measured at M.A. and I.Q.: the relation between them is being given by the following equation:

70 = ^x100 J) … Ixia

or MA = ———————————————- (2)

800 –⁽⁾

When the child’s MA and CA are equal his IQ is 100 and the child is said to be average intelligence. By average intelligence we mean not that the child has IQ = 100, no more, no less. Even if the IQ of a child is greater than 85 and less Than 115 he is said to be of average intelligence.

Thus, there is an average Trend in intelligence. The growth in MA tends to slow down as growth in Height or weight slows down as one reaches maturity.

Till the age of 16 we Generally indicate the intelligence of children by their MA or IQ but after that Age the relative standing of an adolescent is denoted by deciles or percentile Ratings. A docile is one of the nine points that divide a ranked distribution into Ten parts, each containing one-tenth of all cases.

A percentile is one of the 99 Points scores that divide a ranked distribution into groups each of which Contains the scores.

The MA unit has not an equal distance as are centimeters on a meter rod. It means that the difference between an MA of 2 years and an MA of 3 years is not the same as that between an MA of 12 years and an MA of 13 years. We have to determine the unit for each year separately.

A large number of children of various chronological ages are given an intelligence test which contains a sample of tasks. Tasks that are performed by a majority of 7 year old children on the basis of the average performance are given a mental age value of 7 a so on.

Let us exemplify the above statement. In the third revision of the Benet’s for the age CA = 5, we have the following 6 tasks:

1. Identifying absurdities in pictures.

2. Describing similarities (as between coal and wood).

3. Copying a diamond.

4. Solving a social problem.

5. Recognizing appropriate opposites to words.

6. Repeating five digits.

These six tasks can be performed by a majority of 7-year old children in certain country at a certain time. Each of these items has a credit of 2 month if correctly answered. These six items have 7-years MA value.

For each mental age we have tasks. If the sum of the mental age values equals the chronological age, the child will have an IQ of 100. If the 5-year old chill answers all the items on the year V level, 4 of the year VI level, 3 of the yet VII level, 1 of the year VIII level and none of the year IX level his total mental age is 76 months (2 month’s credit for each answer at these levels).

Number of the Item	M.A. (equivalent months)
upto V year level all,	60
VI … 4	8
VII … 3	6
VIII … 1	2
Total	76

IQ = — x 100 60

= 126.6

= 127 nearly.

Thus, child has an IQ on Benet’s test as 127. The child will not always get the same IQ if tested on different days because he may feel better on one day than on another or because his motivation or emotions may be different on two days. He will also not earn the same IQ if tested on the Wechsler test instead of on the Benet. IQ differs from test to-test for one child.